Bene bohn



V U ITED STATES PATENT OFFICE.

RENE BOHN, OF LUDWIGSHAFEN-ON-THE-RHINE, BAVARIA, ASSIGNOR TO THE BADISGHE ANILIN AND SODA FABBIK, OF MANNHEIM, GERMANY.

DYEI NG ANIMAL TEXTILE FABRICS WITH N APHTHAZARIN.

SPECIFICATION forming part of Letters Patent No.379,150, dated March 6, 1888.

Application filed January 5, 1888. Serial No. 259,881. (No specimens.) Patented in Germany April 3. 1887, No. 41,518; in France April 19, 1887, No. 182,962, and in England May 28, 1887, No. 7,833.

To aZZ whom it may concern.-

Be it known that I, RENE BOHN, a citizen of Switzerland, residing at Ludwigshafen-on-the Rhine, in the Kingdom of Bavaria and Empire of Germany, have invented new and useful Improvements in Dyeing Animal Textile Fibers with Naphthazarin, (for which I have obtained patents in Germany,dated April 3, 1887, No. 41,518; in France. dated April 19, 1887, No. 182,962, andin Great Britain, dated May 28, 1887, No. 7,833,) of which the following is a specification.

My invention relates to the production of the hitherto unknown chromium compounds or black to a most delicate gray or slate color,

and resisting remarkably well the action of light, air, soap, and acids. The said naphthazarin colors can also be associated with the chrome-lakes of other fast coloring-matters, and are therefore particularly serviceable for shading 0r saddening the dyes produced by the corresponding employment of alizarin, alizarine-blue, anthragallol coerulein, gall of lavin, and the like.

In carrying out my invention I produce, by way of an example, a fast and deep black chrome-lake of naphthazarin upon wool in the following manner: I take one hundred pounds of well washed and cleansed wool, either in its loose or in its spun, woven, or felted state, and I boil the same during one hour and a half with the requisite amount of water and about three pounds of bichromate of potash and two pounds and ahalfof bitartrate of pot ash. The wool, which has thus fixed the chromium mordant, is then well Washed and subsequently dyed with about four pounds of naphthazarin in a fine state of division-say in the state of a paste containing ten per cent. of the dry col0ring-matter. The temperature of the dye bath ought to be gradually raised from about 30 centigrade to the boiling-point and maintained thereat for, say, from two to three hours,or until thesaid bath is exhausted.

In order to obviate the deleterious effect of ordinary calcareous water in dyeing with naph thazarin, about one part of acetic acid of 1.043 specific gravity (or correspondingly more in the case of water possessing an excessive degree of hardness) is to be added to every thousand parts of the water used for preparing the (lye-bath. In the same manner gray or slate shades are produced within or upon animal textile fibers by employing proportionally smaller amounts of naphthazarin in dyeing.

The before-described mordanting process can likewise be varied by the application of other known chromium mordants-such, for instance, as chrome alum or bichromate of potash, in combination with sulphuric, tartaric, or oxalic acids-and the production of the chromium'lakes of naphthazarin may also be effected in one operation by dyeing in a bath containing naphthazarin jointly with the adequate amount of a chromium mordant; but. I generally prefer to operate in the manner described in the above example.

What I claim as new, and desire to secure by Letters Patent, is

1. As a new article of manufacture, textile fiber, yarn, or cloth, whether knit or woven, having chrome-lakes of naphthazarin produced within or upon the same by exposing the same to the action of chromium mordants and naphthazarin, substantially as described.

2. The within-described process of producing chrome-lakes of naphthazarin within or upon textile fibers by exposing said fibers to the action of chromium mordants and naphthazarin in dyeing, substantially as set forth. In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

RENE BOHN. Witnesses:

J OHANNES BtiTTNER, HERMANN HAUG. 

